How does the char pointer determine the length of the string that needs to be output

Code first:

 1 #include <stdio.h>
 2 #include <string.h>
 3 
 4 
 5 const char g_ip[32] = "123456789";
 6 int func1(const char *ip)
 7 {
 8         printf("ip:%s\n",ip);
 9         printf("ip size:%d\n",sizeof(ip));
10         if(*ip == '\0')
11                 printf("ip is none\n");
12         printf("g_ip:%s\n",g_ip);
13         printf("g_ip size:%d\n",sizeof(g_ip));
14         if(*ip == '\0')
15                 printf("g_ip is none\n");
16         return 0;
17 }
18 
19 int main()
20 {
21         const char ip[32]="ABCDEFG";
22         func1(ip);
23         return 0;
24 }

operation result:

[zyc @ localhost ~] $ ./ a.out
ip:ABCDEFG
ip size:8
g_ip:123456789
g_ip size:32

Look at lines 8 and 9, why ip is a char pointer, but when %s is used, it knows how long printf needs to be? ? ?